Automatic bread maker

ABSTRACT

In an automatic bread maker, after the temperature of temperature control means ( 7 ) reaches a predetermined temperature, the rate of energization of a heater ( 2 ) is fixed by control means ( 14 ), and by doing so, bread, having a predetermined baking color, can be stably prepared.

TECHNICAL FIELD

This invention relates to an automatic bread maker used in common homes.

BACKGROUND ART

A conventional automatic bread maker will now be described withreference to FIGS. 9 and 10. FIG. 9 is a block view showing theconstruction of main portions of the conventional automatic bread maker,and reference numeral 1 denotes a baking chamber, reference numeral 2 aheater constituting heating means, reference numeral 3 a bread bakingvessel removably mounted within the baking chamber, reference numeral 4a motor, reference numeral 5 a belt for transmitting the power of themotor 4, reference numeral 6 a kneading blade driven by the motor 4,reference numeral 7 a temperature detection means abutted against anouter surface of the baking chamber 1 so as to detect the temperature ofthe bread baking vessel 3 for the purpose of a process judgment and atemperature control, reference numeral 8 a lid, reference numeral 9 ayeast charging port for charging yeast therethrough, reference numeral10 a solenoid operatively connected to a valve of the yeast chargingport 9 so as to drop the yeast, reference numeral 11 a control meanswhich includes a microcomputer, and is responsive to a signal from thetemperature detection means 7 for controlling the heater 2, the motor 4and the solenoid 10 so as to bake the bread, reference numeral 12 adisplay portion for displaying the condition and time of the operation,and reference numeral 13 an operating portion for instructing a menu, acourse and the initiation of the cooking (preparation).

When the operating portion 13 is operated to start the cooking, thecontrol means 11 selects one of a plurality of bread-making processes inaccordance with the temperature detected by the temperature detectionmeans 7, and subsequently controls loads of the heater 2, the motor 4and the solenoid 10 in accordance with the selected bread-makingprocess, thereby effecting the bread-making operation.

FIG. 10 is a diagram showing, as one example, the detection temperatureof the temperature detection means 7 and the rate of energization of theheater 2 in the baking step of the conventional automatic bread maker.When the baking step is started, the control means 11 causes the heater2 to be continuously energized. When the temperature within the bakingchamber 1 rises, and the temperature reaches 100° C., the control means11 is responsive to the output of the temperature control means 7 toreduce the rate of energization of the heater 2 to 85%. Then, when thetemperature reaches 150°, the control means 11 reduces the rate ofenergization of the heater 2 to 30%. Thereafter, in accordance with theoutput of the temperature detection means 7, a temperature feedbackcontrol is effected at the energization rate of 30% when the detectedtemperature is not less than 130° C., and at the energization rate of65% when the detected temperature is less than 130° C., and the cookingis completed a predetermined time period (50 minutes) after the bakingis started.

In such a conventional automatic bread maker, since the temperaturedetection means is abutted against the outer surface of the bakingchamber, and is not in contact with the bread baking vessel, thistemperature detection means can not accurately detect the temperature ofthe bread baking vessel, and therefore even if the temperature feedbackcontrol is effected during the baking in order to keep the temperatureof the bread baking vessel constant, the temperature difference betweenthe bread baking vessel and the temperature detection means is largebecause of the influence of the outside (ambient) temperature andovershoot, and if the time, at which a crest and a trough of atemperature ripple come, is shifted even slightly, the baking color isgreatly varied, and there were occasions when though the baking colorwas set to a dark color, it became a light color, and in contrast,though the baking color was set to a light color, it became a darkcolor.

DISCLOSURE OF THE INVENTION

This invention seeks to overcome the above problems, and an object ofthe invention is to provide a bread maker in which even if thetemperature difference between a temperature detection means and a breadbaking vessel is large, bread, having a predetermined baking color, canbe prepared.

The above object of the invention has been achieved by an automaticbread maker comprising a baking chamber having a heater, a bread bakingvessel removably mounted within the baking chamber, temperaturedetection means for detecting a temperature within the baking chamber,and control means responsive to an output of the temperature detectionmeans so as to control the heater and others, wherein after thetemperature of the temperature control means rises to a predeterminedtemperature in a baking step, the rate of energization of the heatingmeans fixed regardless of the temperature of the temperature detectionmeans.

With this construction, the energization of the heating means isstabilized during the baking, and the bread, having a predeterminedbaking color, can be obtained.

According to a first aspect of the invention, there is provided anautomatic bread maker comprising a baking chamber having a heater, abread baking vessel removably mounted within the baking chamber,temperature detection means for detecting a temperature within thebaking chamber, and control means responsive to an output of thetemperature detection means so as to control the heater and others;CHARACTERIZED in that after the temperature of the temperature controlmeans reaches a predetermined temperature in a baking step, the rate ofenergization of the heating means is kept constant. Therefore, atemperature ripple is small, and a predetermined baking color of thebread can be stably obtained.

In a second aspect of the invention, there is further provided timermeans for measuring a rising temperature gradient of the temperaturedetection means at a temperature-rising stage of the baking step, andafter the temperature of the temperature detection means reaches apredetermined temperature, the rate of energization of the heating meansis determined in accordance with a time period measured by the timermeans. Therefore, a predetermined baking color of the bread can bestably obtained regardless of a variation in room temperature and avariation in voltage.

In a third aspect of the invention, in accordance with a time periodmeasured by the timer means, the control means determines theenergization rate before the detection temperature reaches apredetermined temperature, and also determines the energization rateafter the detection temperature reaches a predetermined temperature.Therefore, the temperature rise within the baking chamber can besuppressed, and besides the baking color of the bread can be stabilized.

In a fourth aspect of the invention, the control means determines apredetermined temperature in accordance with a time period measured bythe timer means. Therefore, the baking color of the bread can bestabilized.

In a fifth aspect of the invention, the time measurement is effected bythe timer means, and subsequently in accordance with a time periodmeasured by the timer means, the control means determines a time periodbefore the energization rate is changed, and the time period before thetemperature reaches the peak temperature is determined in accordancewith the measured time period, and therefore the baking color of thebread can be stabilized as in the above case.

In a sixth aspect of the invention, the rate of energization of theheating means after the detection temperature of the temperaturedetection means reaches a predetermined temperature is determined inaccordance with an amount of change of the detection temperature withthe lapse of a predetermined time. Therefore, a predetermined bakingcolor of the bread can be stably obtained regardless of a variation inroom temperature and a variation in voltage.

In a seventh aspect of the invention, there is provided baking colorselection means for selecting a baking color of bread, and the controlmeans determines the rate of energization of the heating means inaccordance with the baking color selected by the baking color selectionmeans. With this construction, a predetermined baking color can bestably obtained.

In an eighth aspect of the invention, there is provided volume selectionmeans for selecting a volume of bread, and the control means determinesthe rate of energization of the heating means in accordance with thevolume selected by the volume selection means. Even when the volume ofthe bread is small, a variation in heater power and a variation in powersource voltage are absorbed in accordance with the selected volume, sothat a predetermined baking color can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block view showing main portions of one preferred embodimentof an automatic bread maker of the present invention;

FIG. 2 is a graph showing a detection temperature and an energizationrate in a baking step of the above embodiment of the invention;

FIG. 3 is a graph showing a detection temperature and an energizationrate in a baking step of another embodiment of the invention;

FIG. 4 is a graph showing a detection temperature and an energizationrate in a baking step of a further embodiment of the invention;

FIG. 5 is a graph showing a detection temperature and an energizationrate in a baking step of a further embodiment of the invention;

FIG. 6 is a graph showing a detection temperature and an energizationrate in a baking step of a further embodiment of the invention;

FIG. 7 is a graph showing a detection temperature and an energizationrate in a baking step of a further embodiment of the invention;

FIG. 8 is a graph showing a detection temperature and an energizationrate in a baking step of a further embodiment of the invention;

FIG. 9 is a block view showing main portions of a conventional automaticbread maker; and

FIG. 10 is a graph showing a detection temperature and an energizationrate in a baking step of the conventional bread maker.

BEST MODE FOR CARRYING OUT THE INVENTION

One preferred embodiment of the present invention will now be describedwith reference to the drawings. FIG. 1 is a block view showing mainportions of the first embodiment of the invention, and those portionsidentical to those of the conventional bread maker are designated byidentical reference numerals, respectively. Control means 14 areresponsive to signals from a temperature detection means 7 and a timermeans 15 to control a heater 2, a motor 4 and a solenoid 10 so as tobake bread. The timer means 15 is responsive to a signal from thecontrol means 14 to measure the time. An operating portion 16 includes abaking color selection means 17 and a volume selection means 18, andthis operating portion 16 sets a menu, a course, the baking color and soon, and instructs the initiation of the cooking (preparation). When theinitiation of the cooking is instructed by the operating portion 16, thecontrol means 14 controls the heater, the motor and the solenoid whileinputting the temperature, detected by the temperature detection means7, thereinto, so as to effect a predetermined bread-making process.Here, the control means 14 and the timer means 15 are contained in aone-chip microcomputer. A display portion comprises a liquid crystaldisplay device.

FIG. 2 is a graph showing the relation between the elapse time from thestart of the baking and the detection temperature detected by thetemperature detection means during a baking step of the bread-makingprocess (The abscissa axis represents the elapse time t from the startof the baking, and the ordinate axis represents the temperature θ), andFIG. 2 also illustrates a diagram showing the rate of energization ofthe heater 2 at this time.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized. When the detectiontemperature of the temperature detection means 7 reaches a firstpredetermined temperature θ1 (60° C. in this embodiment), the timermeans 15 starts the time measurement. Then, when the detectiontemperature of the temperature detection means 7 reaches a secondpredetermined temperature θ2 (90° C. in this embodiment), the timermeans 15 stops the time measurement, and the time ΔT, required for atemperature rise from θ1 to θ2, is obtained. The control means 14further causes the heater 2 to be continuously energized, and when thedetection temperature of the temperature detection means 7 reaches athird predetermined temperature θ3 (155° C. in this embodiment), thecontrol means 14 causes the heater 2 to be energized at such anenergization rate (60% in this embodiment) that the temperature of abread baking vessel can be kept substantially constant if ΔT is not lessthan a first predetermined time T1 (120 seconds in this embodiment) andless than a second predetermined time T2 (180 seconds in thisembodiment). At this time, a sequential feedback control by thetemperature is not effected, and the heater is energized at the constantenergization rate, determined regardless of the detection temperature,until the baking step is finished.

If ΔT is less than T1, the temperature is liable to rise because ofvariations in room temperature and power source voltage, and thereforeif the energization rate after the peak temperature is 60%, thetemperature gradually rises, and therefore the control means 14 reducesthe rate of energization of the heater 2 (to 40% in this embodiment),thereby keeping the temperature of the bread baking vessel substantiallyconstant.

In contrast, if ΔT is not less than T2, the temperature is less liableto rise, and therefore the rate of energization of the heater 2 is setto a lager value (80% in this embodiment).

Therefore, in the construction in which the bread baking vessel 3 is notin contact with the temperature detection means 7, even if the electricpower of the heater fluctuates, and the power source voltage varies, thetemperature of the bread baking vessel 3 after the third predeterminedtemperature θ3 can be kept substantially constant without beingsubjected to a large ripple, and the prepared bread can have apredetermined baking color.

The embodiment described here is directed to the second aspect of theinvention, but if the influences of variations in room temperature andpower source voltage are small, there can be used a method in which themeasurement of ΔT is not effected, and the energization rate after thepeak temperature is fixed to a constant value, and even with thismethod, the control can be effected more stably than the conventionalfeedback control, and this case is directed to the first aspect of theinvention.

FIG. 3 is a graph explanatory of the third aspect of the invention, andmore specifically shows a graph showing the relation between the elapsetime from the start of the baking and the detection temperature of thetemperature detection means 7, and FIG. 3 also illustrates a diagramshowing the rate of energization of the heater 2 at this time. As inFIG. 2, the abscissa axis represents the elapse time t from the start ofthe baking, and the ordinate axis represents the temperature θ.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized (at an energization rate of1005). When the detection temperature of the temperature detection means7 reaches a first predetermined temperature θ1 (60° C. in thisembodiment), the timer means starts the time measurement. Then, when thedetection temperature of the temperature detection means 7 reaches asecond predetermined temperature θ2 (90° C. in this embodiment), thetimer means stops the time measurement, and the time ΔT, required for atemperature rise from θ1 to θ2, is obtained. At this time, when thedetection temperature of the temperature detection means 7 exceeds θ2,the control means 14 reduces the energization rate (to 80% in thisembodiment) if ΔT is less than a predetermined time T1 (120 seconds inthis embodiment), and the control means 14 causes the heater 2 to becontinuously energized if ΔT is not less than T1.

Then, when the detection temperature of the temperature detection means7 exceeds a third predetermined temperature θ3, the control means 14causes the heater 2 to be energized at such an energization rate (60% inthis embodiment) after the third predetermined temperature (which rateis determined in accordance with ΔT) that the temperature of the breadbaking vessel can be kept substantially constant even if there arevariations in power source voltage and room temperature as in claim 2,and when a predetermined time (50 minutes in this embodiment) of thebaking step elapses, the bread-making process is finished.

With this method, there can be prevented a situation in which because ofa variation in electric power of the heater and a variation in powersource voltage, the temperature within the baking chamber 1 is subjectedto a large ripple by overshoot of the feedback control, and becomesdifferent from the temperature of the temperature detection means, andunduly rises. Therefore, the prepared bread can have a predeterminedcolor.

In this embodiment, although the heater 2 is continuously energized forthe time period from the start of the baking to the time when thetemperature reaches θ2, there may be used a method in which the heater 2is energized at a constant energization rate for the time period fromthe start of the baking to the time when the temperature reaches θ2, andif ΔT is not less than a predetermined time T2, the energization rate isincreased for the time period during which the temperature rises from θ2to θ3.

FIG. 4 is a graph explanatory of the invention of claim 4, and morespecifically shows a graph showing the relation between the elapse timefrom the start of the baking in a baking step and the detectiontemperature detected by the temperature detection means 7, and FIG. 4also illustrates a diagram showing the rate of energization of theheater 2 at this time. The abscissa axis represents the elapse time tfrom the start of the baking, and the ordinate axis represents thetemperature θ.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized. When the detectiontemperature of the temperature detection means 7 reaches a firstpredetermined temperature θ1 (60° C. in this embodiment), the timermeans starts the time measurement. Then, when the detection temperatureof the temperature detection means 7 reaches a second predeterminedtemperature θ2 (90° C. in this embodiment), the timer means stops thetime measurement, and the time ΔT, required for a temperature rise fromθ1 to θ2, is obtained. Then, the control means 14 causes the heater 2 tobe continuously energized until the temperature reaches a thirdpredetermined temperature θ3 (140° C. in this embodiment). If ΔT is notless than T1 and less than T2 (T1≦ΔT<T2), θ3=155° C. (no correction) isobtained, and if ΔT is less than T1 (ΔT<T1), θ3=150° C. (correction: −5°C. ) is obtained, and if ΔT is not less than T2 (T2≧ΔT), θ3=160° C.(correction: +5° C.) is obtained. When the detection temperature reachesθ3, the control means 14 causes the heater 2 to be energized at such anenergization rate that the temperature of the bread baking vessel can bekept constant, and when the time of the baking step becomes 50 minutes,the break-making process is finished.

With this method, the peak temperature can be corrected in accordancewith the time of rise of the detection temperature, and the preparedbread can have a predetermined baking color.

FIG. 5 is a graph explanatory of the invention of claim 5, and morespecifically shows a graph showing the relation between the elapse timefrom the start of the baking in a baking step and the detectiontemperature detected by the temperature detection means 7, and FIG. 5also illustrates a diagram showing the rate of energization of theheater 2 at this time. The abscissa axis represents the elapse time tfrom the start of the baking, and the ordinate axis represents thetemperature θ.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized. When the detectiontemperature of the temperature detection means 7 reaches a firstpredetermined temperature θ1 (60° C. in this embodiment), the timermeans 15 starts the time measurement. Then, when the detectiontemperature of the temperature detection means 7 reaches a secondpredetermined temperature θ2 (90° C. in this embodiment), the timermeans stops the time measurement, and the time ΔT, required for atemperature rise from θ1 to θ2, is obtained. When the detectiontemperature of the temperature measurement means 7 exceeds θ2, thecontrol means 14 sets a continuous energization time to 10 minutes(standard time) if ΔT is not less than T1 (120 seconds in thisembodiment) and less than T2 (180 seconds in this embodiment), and thecontrol means 14 sets the continuous energization time to 8 minutes(correction: −2 minutes) if ΔT is less than the predetermined time T1,and the control means 14 sets the continuous energization time to 12minutes (correction: +2 minutes) if ΔT is not less than T2. In thismanner, the heater 2 is continuously energized under the control of thecontrol means 14. After the lapse of the continuous energization time,the control means 14 causes the heater 2 to be energized at such anenergization rate (60% in this embodiment) that the temperature of thebread baking vessel can be kept substantially constant, and when thetime of the baking step becomes 50 minutes, the bread-making process isfinished.

With this method, the time of the heating by the continuous energizationcan be corrected in accordance with the time of rise of the detectiontemperature, and the prepared bread can have a predetermined bakingcolor.

FIG. 6 is a graph explanatory of the invention of claim 6, and morespecifically shows a graph showing the relation between the elapse timefrom the start of the baking in a baking step and the detectiontemperature detected by the temperature detection means 7, and FIG. 6also illustrates a diagram showing the rate of energization of theheater 2 at this time. The abscissa axis represents the elapse time tfrom the start of the baking, and the ordinate axis represents thetemperature θ.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized. By the temperature detectionmeans 7, a detection temperature k1 is obtained a predetermined time α(240 seconds in this embodiment) after the start of the baking step, anda detection temperature K2 is obtained a predetermined time β (400seconds in this embodiment) after the start of the baking step, and thetemperature difference Δ between the two is obtained. When the detectiontemperature of the temperature detection means 7 reaches a thirdpredetermined temperature θ3 (155° C. in this embodiment), the controlmeans 14 controls the heater 2 to such an energization rate (60% in thisembodiment) (which is determined experimentally) that the temperature ofthe bread baking vessel can be kept constant if Δk is not less than apredetermined temperature difference K1 (25° C. in this embodiment) andless than a predetermined temperature difference K2 (35° C. in thisembodiment). If Δk is less than K1, the control means 14 reduces therate of energization of the heater 2 (to 40% in this embodiment) sincethe electric power is increased because of variations in heater powerand power source voltage. If Δk is not less than K2, the control means14 increases the rate of energization of the heater 2 (to 80% in thisembodiment). The energization of the heater 2 is effected until apredetermined time (50 minutes) of the baking step elapses, and thebread-making process is finished.

With this method, even if the power of the heat fluctuates, and thepower source voltage varies, the prepared bread can have a predeterminedbaking color.

FIG. 7 is a graph explanatory of the invention of claim 7, and morespecifically shows a graph showing the relation between the elapse timefrom the start of the baking (in the baking step in which the bakingcolor is selected by the baking color selection means 17) and thedetection temperature detected by the temperature detection means 7, andFIG. 7 also illustrates a diagram showing the rate of energization ofthe heater 2 at this time. The abscissa axis represents the elapse timet from the start of the baking, and the ordinate axis represents thetemperature θ.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized. When the detectiontemperature of the temperature detection means 7 reaches a firstpredetermined temperature θ1 (60° C. in this embodiment), the timermeans 15 starts the time measurement. Then, when the detectiontemperature of the temperature detection means 7 reaches a secondpredetermined temperature θ2 (90° C. in this embodiment), the timermeans stops the time measurement, and the time ΔT, required for atemperature rise from θ1 to θ2, is obtained. If the baking color,selected by the baking color selection means 17, is either of “dark” and“medium”, the control means 14 causes the heater 2 to be continuouslyenergized until the temperature reaches a third predeterminedtemperature θ3 (165° C. in the case of “dark”, and 155° C. in the caseof “medium”). If the selected baking color is “light”, the control means14 causes the heater 2 to be energized at the energization rate of 80%until the temperature reaches the predetermined third temperature θ3(140° C. in the case of “light”). After the temperature reaches θ3, theheater is energized at such an energization rate that the temperature ofthe bread baking vessel can be kept constant, and the energization iscontinued until a predetermined time (50 minutes) of the baking stepelapses, and the bread-making process is finished.

With this method, even when the light baking color is selected, thetemperature difference between the detection temperature of thetemperature detection means 7 and the temperature of the bread bakingvessel can be made small, and the prepared bread can have apredetermined baking color corresponding to the selected baking color.

FIG. 8 is a graph explanatory of the invention of claim 8, and morespecifically shows a graph showing the relation between the elapse timefrom the start of the baking (in the baking step in which the volume isselected by the volume selection means 18) and the detection temperaturedetected by the temperature detection means 7, and FIG. 8 alsoillustrates a diagram showing the rate of energization of the heater 2at this time. The abscissa axis represents the elapse time t from thestart of baking, and the ordinate axis represents the temperature θ.

When the process shifts to the baking step, the control means 14 causesthe heater 2 to be continuously energized. When the detectiontemperature of the temperature detection means 7 reaches a firstpredetermined temperature θ1 (60° C. in this embodiment), the timermeans starts the time measurement. Then, when the detection temperatureof the temperature detection means 7 reaches a second predeterminedtemperature θ2 (90° C. in this embodiment), the timer means stops thetime measurement, and the time ΔT, required for a temperature rise fromθ1 to θ2, is obtained. If either of “2.5 pound” and “2 pound” isselected by the volume selection means 18, the control means 14 causesthe heater 2 to be energized at an energization rate of 60% after thedetection temperature of the temperature detection means 7 reaches θ3,and if “1.5 pound” is selected by the volume selection means 18, thecontrol means 14 causes he heater 2 to be energized at the energizationrate of 50% after the temperature reaches θ3, and when a predeterminedtime (50 minutes) elapses from the start of the baking step, thebread-making process is finished.

With this method, the energization rate can be corrected in accordancewith the selected bread volume, and the predetermined baking color canbe obtained regardless of the volume.

These inventions of the claims can be used in combination with eachother.

INDUSTRIAL APPLICABILITY

In the first aspect of the invention, even in the structure in which theordinary feedback-type temperature control in the baking step, thetemperature detection means is spaced from the bread baking vessel, andthe temperature difference between the two is large, the temperature ofthe bread baking vessel can be kept substantially constant, and whenselecting the baking color, the baking color can be stably set merely bysetting the rate of energization of the heater to an appropriate value.

In the second aspect of the invention, the energization rate after thedetection temperature reaches the predetermined temperature is changedin accordance with the time required for a temperature rise between thetwo temperature values in the baking step, the temperature within thebaking chamber is prevented from become unstable even if the electricpower of the heater fluctuates, and the room temperature varies, and thetemperature of the bread baking vessel can be kept substantiallyconstant regardless of the temperature of the temperature detectionmeans, and the prepared bread can have a predetermined baking color.

In the third aspect of the invention, the energization rate before thedetection temperature reaches the peak temperature is changed inaccordance with the time required for a temperature rise between the twotemperature values in the baking step, and by doing so, overshoot at atemperature near to the peak temperature is reduced, and even if thepower of the heater fluctuates, and the power source voltage and theroom temperature vary, the temperature of the bread baking vessel can bekept substantially constant regardless of the temperature of thetemperature detection means, and the prepared bread can have apredetermined baking color.

In the fourth aspect of the invention, the peak temperature is changedin accordance with the time required for a temperature rise between thetwo temperature values in the baking step, and by doing so, overshoot isreduced without reducing the energizing power at a temperature near tothe peak temperature, and even if the power of the heater fluctuates,and the power source voltage and the room temperature vary, thetemperature of the bread baking vessel can be kept substantiallyconstant regardless of the temperature of the temperature detectionmeans, and the prepared bread can have a predetermined baking color.

In the fifth aspect of the invention, the time before the detectiontemperature reaches the peak temperature is changed in accordance withthe time required for a temperature rise between the two temperaturevalues in the baking step, and by doing so, even if the power of theheater, the power source voltage and the room temperature vary, the peaktemperature can be so determined that overshoot can be reduced, and thatthe energizing power can be increased as much as possible, and the breadcan be prepared more stably.

In the sixth aspect of the invention, the rate of energization of theheater after the detection temperature reaches the predeterminedtemperature is changed in accordance with the amount of rise of thedetection temperature for the predetermined time period, and thereforeeven if the power of the heater fluctuates, and the power source voltageand the room temperature vary, the prepared bread can have apredetermined baking color as in the aspects 2 to 5 of the invention.

In the seventh aspect of the invention, the energization rate after thepeak temperature is determined in accordance with the selected bakingcolor, and therefore there will not be encountered a reverse phenomenonin which the baking color becomes darker when selecting “light” thanwhen selecting “medium”, and the prepared bread can have the selectedbaking color.

In the eighth aspect of the invention, the energization rate after thedetection temperature reaches the peak temperature is changed inaccordance with the selected volume, and therefore there will not beencountered a reverse phenomenon in which at the time of changing thevolume, the baking color becomes darker when selecting “light” than whenselecting “medium”, and the baking color of the prepared bread canstably have the predetermined color regardless of the volume of thebread.

What is claimed is:
 1. An automatic bread maker, comprising: a bakingchamber having a heater; a bread baking vessel removably mounted withinsaid baking chamber; temperature detection means for detecting atemperature within said baking chamber; and control means responsive toan output of said temperature detection means so as to control saidheater and others; wherein after the temperature of said temperaturecontrol means reaches a predetermined temperature in a baking step, therate of energization of said heating means is kept constant.
 2. Anautomatic bread maker according to claim 1, further comprising timermeans for measuring a rising temperature gradient of said temperaturedetection means at a temperature-rising stage of said baking step, andafter the temperature of said temperature detection means reaches apredetermined temperature, the rate of energization of said heatingmeans is determined in accordance with a time period measured by saidtimer means.
 3. An automatic bread maker according to claim 2, whereinin accordance with a time period measured by said timer means, saidcontrol means determines the energization rate before the detectiontemperature reaches a predetermined temperature, and determines theenergization rate after the detection temperature reaches apredetermined temperature.
 4. An automatic bread maker according toclaim 2, wherein said control means determines a predeterminedtemperature in accordance with a time period measured by said timermeans.
 5. An automatic bread maker according to claim 2, wherein thetime measurement is effected by said timer means, and subsequently inaccordance with a time period measured by said timer means, said controlmeans determines a time period before the energization rate is changed.6. An automatic bread maker according to claim 1, wherein the rate ofenergization of said heating means after the detection temperature ofsaid temperature detection means reaches a predetermined temperature isdetermined in accordance with an amount of change of the detectiontemperature with the lapse of a predetermined time.
 7. An automaticbread maker according to any one of claims 1 to 6, in which there isprovided baking color selection means for selecting a baking color ofbread, and said control means determines the rate of energization ofsaid heating means in accordance with the baking color selected by saidbaking color selection means.
 8. An automatic bread maker according toany one of claims 1 to 6, in which there is provided volume selectionmeans for selecting a volume of bread, and said control means determinesthe rate of energization of said heating means in accordance with thevolume selected by said volume selection means.